This is an open label trial to evaluate the effect of concomitant oral contraceptives and IM medroxyprogesterone on ZDV metabolism and intracellular pharmacokinetics in women. Secondary gaols are to investigate the effects of oral contraceptives or IM medroxyprogesterone on plasma and genital tract HIV load and to explore the effect of gender on the pharmacokinetics of indinavir. Volunteers will stay in the GCRC on study days when serial blood draws are required to collect pharmacokinetic data (8-12 hours).